As described in JP9-290197A, there has been conventionally known a liquid processing apparatus including: a hollow bottom plate configured to hold an object to be processed such as a semiconductor wafer (hereinafter referred to also as “wafer”); a rotational shaft fixedly connected to the bottom plate, the rotational shaft being configured to be rotated by a spin motor; a supply duct configured to supply a cleaning liquid to a wafer held by the bottom plate; and a substrate lift pin capable of being raised so as to support the wafer from below.
In the conventional liquid processing apparatus, there is a possibility that cleaning liquids, such as a chemical liquid and a rinse liquid used for cleaning a wafer, might adhere to the substrate lift pin via a through hole. Thus, after drying a wafer, when the wafer is raised by the substrate lift pin and is delivered to a transfer robot, liquid droplets of the cleaning liquid adhering to the substrate lift pin may adhere to a rear surface of the wafer.
When the cleaning liquid adheres to the wafer, watermarks are formed on the wafer itself to which the liquid droplets adhere. In addition thereto, watermarks are generated on other wafers contained in a carrier into which the wafer has been brought, because of an increase in humidity in the carrier.